Add sync error logging, extend error flash, fix unload saves

- Log workforce sync errors to backend stdout so they appear in docker logs
- Extend error flash from 5s to 15s so errors are readable
- Replace sendBeacon (POST-only) with keepalive fetch (PUT) on unload —
  sendBeacon was hitting 404s on all three unload saves

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/node_modules/@babel/helper-skip-transparent-expression-wrappers/lib/index.js

@@ -0,0 +1,34 @@
+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.isTransparentExprWrapper = isTransparentExprWrapper;
+exports.skipTransparentExprWrapperNodes = skipTransparentExprWrapperNodes;
+exports.skipTransparentExprWrappers = skipTransparentExprWrappers;
+var _t = require("@babel/types");
+const {
+  isParenthesizedExpression,
+  isTSAsExpression,
+  isTSNonNullExpression,
+  isTSSatisfiesExpression,
+  isTSTypeAssertion,
+  isTypeCastExpression
+} = _t;
+function isTransparentExprWrapper(node) {
+  return isTSAsExpression(node) || isTSSatisfiesExpression(node) || isTSTypeAssertion(node) || isTSNonNullExpression(node) || isTypeCastExpression(node) || isParenthesizedExpression(node);
+}
+function skipTransparentExprWrappers(path) {
+  while (isTransparentExprWrapper(path.node)) {
+    path = path.get("expression");
+  }
+  return path;
+}
+function skipTransparentExprWrapperNodes(node) {
+  while (isTransparentExprWrapper(node)) {
+    node = node.expression;
+  }
+  return node;
+}
+
+//# sourceMappingURL=index.js.map